Opto-isolators, including light emitters and light detectors which are housed in a single package, are well-known in the optoelectronics art and have been commercially available for the past few years. These devices typically include a light-emitting diode (LED), such as a discrete gallium arsenide, gallium phosphide, or gallium arsenide phosphide diode, which is encapsulated in a small package together with a discrete detector, such as a silicon photodetector. These opto-isolator devices have demonstrated their usefulness in a variety of optoelectronic applications including high performance voltage regulators, subsystem couplers, actuator switches, and in various types of logic circuits. Furthermore, these devices have replaced such time honored components as interstage transformers and relays, as well as amplifier coupling and feedback networks. Thus, the very substantial interest in and utility of these devices are manifest. Such a device is disclosed, for example, in U.S. Pat. No. 3,727,064 and in numerous other technical publications.